ragas
Ragas is a Python framework for evaluating and optimizing Large Language Model applications through objective metrics, automated test generation, and production-aligned feedback loops. It provides pre-built evaluation metrics tailored for LLM and RAG systems, integrates with popular frameworks like LangChain, and helps teams move from subjective assessments to data-driven evaluation workflows.
Key facts
Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.
| Field | Value |
|---|---|
| Repository | vibrantlabsai/ragas |
| Owner | vibrantlabsai |
| Primary language | Python |
| License | Apache-2.0 — OSI-approved |
| Stars | 14.7k |
| Forks | 1.5k |
| Open issues | 478 |
| Latest release | v0.4.3 (2026-01-13) |
| Last updated | 2026-02-24 |
| Source | https://github.com/vibrantlabsai/ragas |
What ragas is
Ragas is an Apache-2.0 licensed Python library that implements LLM-based and traditional metrics for evaluating LLM outputs. It supports async/await patterns, integrates with major LLM clients (OpenAI, etc.), offers templated quickstart projects for RAG evaluation, and includes instrumentation for production data feedback loops.
Get the ragas source
Clone the repository and explore it locally.
git clone https://github.com/vibrantlabsai/ragas.gitcd ragas# follow the project's README for install & configurationNeed it deployed, integrated, or customized instead? DEV.co ships production installs.
Best use cases
Implementation considerations
- Initialize LLM client (e.g., AsyncOpenAI) and configure API credentials; environment variable setup required for authentication.
- Select appropriate metrics for your use case (DiscreteMetric, Aspect Critique, etc.) and customize evaluation prompts if needed.
- Plan async execution model; Ragas uses asyncio extensively, requiring async-compatible application architecture.
- Cost estimation: budget for LLM API calls; metric scoring cost depends on model selection and evaluation frequency.
- Test with a small dataset first; validate metric behavior and prompt wording before scaling to production evaluation runs.
When to avoid it — and what to weigh
- Real-time Latency-Critical Systems — Ragas evaluation is LLM-based and async, introducing network latency. Not suitable for systems requiring sub-100ms evaluation response times.
- Offline-Only or Air-Gapped Deployments — Requires external LLM API calls (OpenAI, etc.) for scoring. Cannot run purely offline without custom LLM integration or local model setup.
- Non-Python Technical Stacks — Pure Python library with no native Go, Java, or Node.js SDKs. Would require wrapping or API gateway for non-Python applications.
- Low-Cost Evaluation at Scale — LLM-based metrics incur per-call costs. High-volume evaluation could accumulate significant API charges depending on metric selection.
License & commercial use
Apache License 2.0 is a permissive OSI-approved license allowing commercial use, modification, and distribution.
Apache-2.0 permits commercial use, including in proprietary products. Retain license and copyright notices in derivatives. No explicit warranty; review LICENSE file for indemnification limits before production deployment.
DEV.co evaluation signals
Editorial assessment — not user reviews. Directional, with an explicit confidence level.
| Signal | Assessment |
|---|---|
| Maintenance | Active |
| Documentation | Adequate |
| License clarity | Clear |
| Deployment complexity | Low |
| DEV.co fit | Strong |
| Assessment confidence | High |
No data provided on security audits, vulnerability disclosure process, or threat model. LLM-based evaluation sends data to external APIs; ensure API keys and evaluation payloads comply with data governance policies. Anonymized analytics enabled by default; review _analytics.py code if data residency is critical. No security claims inferred without supporting evidence.
Alternatives to consider
LlamaIndex (formerly Gpt-Index)
Offers evaluation modules alongside RAG orchestration; integrated approach if building end-to-end RAG systems. Requires more framework coupling.
DeepEval
Comparable LLM-based evaluation library; may offer different metric sets or integrations. Direct competitor in evaluation-focused tooling.
Custom Evaluation Scripts with LLM APIs
Lower-level approach using OpenAI/Anthropic directly; full control but higher development overhead and no pre-built metrics or templates.
Build on ragas with DEV.co software developers
Ragas offers a low-barrier entry point with quickstart templates and active community support. Start with the rag_eval template, test with your data, and scale evaluation workflows systematically.
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ragas FAQ
Can I use Ragas without paying for LLM API calls?
Is Ragas production-ready?
Does Ragas work with non-OpenAI LLMs?
What is the 'RAGAS_DO_NOT_TRACK' environment variable for?
Work with a software development agency
Adopting ragas is usually one piece of a larger software development effort. As a software development agency, DEV.co provides software development services and web development expertise — pairing senior software developers and web developers with your team to design, build, and operate ai frameworks software in production.
Ready to improve LLM evaluation?
Ragas offers a low-barrier entry point with quickstart templates and active community support. Start with the rag_eval template, test with your data, and scale evaluation workflows systematically.